package com.juick.server.protocol;

import com.juick.Message;
import com.juick.Tag;
import com.juick.User;
import com.juick.formatters.PlainTextFormatter;
import com.juick.server.helpers.TagStats;
import com.juick.server.protocol.annotation.UserCommand;
import com.juick.service.*;
import com.juick.util.TagUtils;
import org.apache.commons.lang3.math.NumberUtils;

import javax.inject.Inject;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

/**
 * Created by oxpa on 22.03.16.
 */

public class JuickProtocol {

    private String baseUri;
    private ProtocolListener listener;

    @Inject
    UserService userService;
    @Inject
    TagService tagService;
    @Inject
    MessagesService messagesService;
    @Inject
    SubscriptionService subscriptionService;
    @Inject
    PMQueriesService pmQueriesService;
    @Inject
    PrivacyQueriesService privacyQueriesService;
    @Inject
    ShowQueriesService showQueriesService;

    public JuickProtocol(String baseUri) {
        this.baseUri = baseUri;
    }

    /**
     * find command by pattern and invoke
     * @param user who send command
     * @param userInput given by user
     * @return command result
     * @throws InvocationTargetException
     * @throws IllegalAccessException
     * @throws NoSuchMethodException
     */
    public ProtocolReply getReply(User user, String userInput) throws InvocationTargetException,
            IllegalAccessException, NoSuchMethodException {
        Optional<Method> cmd =  Arrays.stream(getClass().getDeclaredMethods())
                .filter(m -> m.isAnnotationPresent(UserCommand.class))
                .filter(m -> Pattern.compile(m.getAnnotation(UserCommand.class).pattern(),
                        m.getAnnotation(UserCommand.class).patternFlags()).matcher(userInput).matches())
                .findFirst();
        if (!cmd.isPresent()) {
            // default command - post as new message
            return postMessage(user, userInput);
        } else {
            Matcher matcher = Pattern.compile(cmd.get().getAnnotation(UserCommand.class).pattern(),
                    cmd.get().getAnnotation(UserCommand.class).patternFlags()).matcher(userInput);
            List<String> groups = new ArrayList<>();
            while (matcher.find()) {
                for (int i = 1; i <= matcher.groupCount(); i++) {
                    groups.add(matcher.group(i));
                }
            }
            return (ProtocolReply) getClass().getMethod(cmd.get().getName(), User.class, String[].class)
                    .invoke(this, user, groups.toArray(new String[groups.size()]));
        }
    }

    public ProtocolReply postMessage(User user, String input) {
        List<Tag> tags = tagService.fromString(input, false);
        String body = input.substring(TagUtils.toString(tags).length());
        int mid = messagesService.createMessage(user.getUid(), body, null, tags);
        subscriptionService.subscribeMessage(mid, user.getUid());
        return new ProtocolReply("New message posted.\n#" + mid + " " + baseUri + mid);
    }

    @UserCommand(pattern = "^#(\\++)$", help = "#+ - Show last Juick messages (#++ - second page, ...)")
    public ProtocolReply commandLast(User user, String... arguments) {
        // number of + is the page count
        int page = arguments[0].length() - 1;
        List<Integer> mids = messagesService.getAll(user.getUid(), page);
        List<Message> messages = messagesService.getMessages(mids);
        return new ProtocolReply("Last messages: \n" + String.join("\n", messages.stream().map(PlainTextFormatter::formatPost)
                .collect(Collectors.toList())));
    }

    @UserCommand(pattern = "^\\s*bl\\s*$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "BL - Show your blacklist")
    public ProtocolReply commandBL(User user_from, String... arguments) {
        List<User> blusers;
        List<String> bltags;

        blusers = userService.getUserBLUsers(user_from.getUid());
        bltags = tagService.getUserBLTags(user_from.getUid());


        String txt = "";
        if (bltags.size() > 0) {
            for (String bltag : bltags) {
                txt += "*" + bltag + "\n";
            }

            if (blusers.size() > 0) {
                txt += "\n";
            }
        }
        if (blusers.size() > 0) {
            for (User bluser : blusers) {
                txt += "@" + bluser.getName() + "\n";
            }
        }
        if (txt.isEmpty()) {
            txt = "You don't have any users or tags in your blacklist.";
        }
        return new ProtocolReply(txt);
    }

    @UserCommand(pattern = "^bl\\s+@([^\\s\\n\\+]+)", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "BL @username - add @username to your blacklist")
    public ProtocolReply blacklistUser(User from, String... arguments) {
        User blUser = userService.getUserByName(arguments[0]);
        if (blUser != null) {
            PrivacyQueriesService.PrivacyResult result = privacyQueriesService.blacklistUser(from, blUser);
            if (result == PrivacyQueriesService.PrivacyResult.Added) {
                return new ProtocolReply("User added to your blacklist");
            } else {
                return new ProtocolReply("User removed from your blacklist");
            }
        }
        return new ProtocolReply("User not found");
    }

    @UserCommand(pattern = "^bl\\s\\*(\\S+)$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "BL *tag - add *tag to your blacklist")
    public ProtocolReply blacklistTag(User from, String... arguments) {
        User blUser = userService.getUserByName(arguments[0]);
        if (blUser != null) {
            Tag tag = tagService.getTag(arguments[0], false);
            if (tag != null) {
                PrivacyQueriesService.PrivacyResult result = privacyQueriesService.blacklistTag(from, tag);
                if (result == PrivacyQueriesService.PrivacyResult.Added) {
                    return new ProtocolReply("Tag added to your blacklist");
                } else {
                    return new ProtocolReply("Tag removed from your blacklist");
                }
            }
        }
        return new ProtocolReply("Tag not found");
    }

    @UserCommand(pattern = "@", help = "@ - Show recommendations and popular personal blogs")
    public ProtocolReply commandUsers(User currentUser, String... args) {
        StringBuilder msg = new StringBuilder();
        msg.append("Recommended blogs");
        List<String> recommendedUsers = showQueriesService.getRecommendedUsers(currentUser);
        if (recommendedUsers.size() > 0) {
            for (String user : recommendedUsers) {
                msg.append("\n@").append(user);
            }
        } else {
            msg.append("\nNo recommendations now. Subscribe to more blogs. ;)");
        }
        msg.append("\n\nTop 10 personal blogs:");
        List<String> topUsers = showQueriesService.getTopUsers();
        if (topUsers.size() > 0) {
            for (String user : topUsers) {
                msg.append("\n@").append(user);
            }
        } else {
            msg.append("\nNo top users. Empty DB? ;)");
        }
        return new ProtocolReply(msg.toString());
    }

    @UserCommand(pattern = "\\*", help = "* - Show your tags")
    public ProtocolReply commandTags(User currentUser, String... args) {
        List<TagStats> tags = tagService.getUserTagStats(currentUser.getUid());
        String msg = "Your tags: (tag - messages)\n" +
                tags.stream()
                        .map(t -> String.format("\n*%s - %d", t.getTag().getName(), t.getUsageCount())).collect(Collectors.joining());
        return new ProtocolReply(msg);
    }

    @UserCommand(pattern = "!", help = "! - Show your favorite messages")
    public ProtocolReply commandFavorites(User currentUser, String... args) {
        List<Integer> mids = messagesService.getUserRecommendations(currentUser.getUid(), 0);
        if (mids.size() > 0) {
            List<Message> messages = messagesService.getMessages(mids);
            return new ProtocolReply("Favorite messages: \n" + String.join("\n", messages.stream().map(PlainTextFormatter::formatPost)
                    .collect(Collectors.toList())));
        }
        return new ProtocolReply("No favorite messages, try to \"like\" something ;)");
    }

    @UserCommand(pattern = "^\\@([^\\s\\n\\+]+)(\\+?)$",
            help = "@username+ - Show user's info and last 10 messages (@username++ - second page, ..)")
    public ProtocolReply commandUser(User user, String... arguments) {
        User blogUser = userService.getUserByName(arguments[0]);
        int page = arguments[1].length();
        if (blogUser != null) {
            List<Integer> mids = messagesService.getUserBlog(blogUser.getUid(), 0, page);
            List<Message> messages = messagesService.getMessages(mids);
            return new ProtocolReply(String.format("Last messages from @%s:\n%s", arguments[0],
                    String.join("\n", messages.stream()
                            .map(PlainTextFormatter::formatPost).collect(Collectors.toList()))));
        }
        return new ProtocolReply("User not found");
    }

    @UserCommand(pattern = "^\\s*d\\s*\\#([0-9]+)\\s*$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "D #12345 - delete the message")
    public ProtocolReply commandDel(User user, String... args) {
        int mid = NumberUtils.toInt(args[0], 0);
        if (messagesService.deleteMessage(user.getUid(), mid)) {
            return new ProtocolReply(String.format("Message %s deleted", mid));
        }
        return new ProtocolReply("Error");
    }

    @UserCommand(pattern = "^\\s*login\\s*$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "LOGIN - log in to Juick website")
    public ProtocolReply commandLogin(User user, String... arguments) {
        return new ProtocolReply(baseUri + "?" + userService.getHashByUID(user.getUid()));
    }

    @UserCommand(pattern = "^(#+)$", help = "# - Show last messages from your feed (## - second page, ...)")
    public ProtocolReply commandMyFeed(User user, String... arguments) {
        // number of # is the page count
        int page = arguments[0].length() - 1;
        List<Integer> mids = messagesService.getMyFeed(user.getUid(), page);
        List<Message> messages = messagesService.getMessages(mids);
        // TODO: add instructions for empty feed
        return new ProtocolReply("Your feed: \n" + String.join("\n",
                messages.stream().map(PlainTextFormatter::formatPost).collect(Collectors.toList())));
    }

    @UserCommand(pattern = "^\\s*(on|off)\\s*$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "ON/OFF - Enable/disable subscriptions delivery")
    public ProtocolReply commandOnOff(User user, String[] input) {
        UserService.ActiveStatus newStatus;
        String retValUpdated;
        if (input[0].toLowerCase().equals("on")) {
            newStatus = UserService.ActiveStatus.Active;
            retValUpdated = "Notifications are activated for " + user.getJid();
        } else {
            newStatus = UserService.ActiveStatus.Inactive;
            retValUpdated = "Notifications are disabled for " + user.getJid();
        }

        if (userService.setActiveStatusForJID(user.getJid(), newStatus)) {
            return new ProtocolReply(retValUpdated);
        } else {
            return new ProtocolReply(String.format("Subscriptions status for %s was not changed", user.getJid()));
        }
    }

    @UserCommand(pattern = "^\\s*ping\\s*$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "PING - returns you a PONG")
    public ProtocolReply commandPing(User user, String[] input) {
        return new ProtocolReply("PONG");
    }

    @UserCommand(pattern = "^\\@(\\S+)\\s+([\\s\\S]+)$", help = "@username message - send PM to username")
    public ProtocolReply commandPM(User user_from, String... arguments) {
        String user_to = arguments[0];
        String body = arguments[1];

        User toUser = userService.getUserByName(user_to);

        if (toUser.getUid() > 0) {
            if (!userService.isInBLAny(toUser.getUid(), user_from.getUid())) {
                if (pmQueriesService.createPM(user_from.getUid(), toUser.getUid(), body)) {
                    listener.privateMessage(user_from, toUser, body);
                    return new ProtocolReply("Private message sent");
                }
            }
        }
        return new ProtocolReply("Error");
    }

    @UserCommand(pattern = "^#(\\d+)(\\+?)$", help = "#1234 - Show message (#1234+ - message with replies)")
    public ProtocolReply commandShow(User user, String... arguments) {
        boolean showReplies = arguments[1].length() > 0;
        int mid;
        try {
            mid = Integer.parseInt(arguments[0]);
        } catch (NumberFormatException e) {
            return new ProtocolReply("Error");
        }
        Message msg = messagesService.getMessage(mid);
        if (msg != null) {
            if (showReplies) {
                List<Message> replies = messagesService.getReplies(mid);
                replies.add(0, msg);
                return new ProtocolReply(String.join("\n",
                        replies.stream().map(PlainTextFormatter::formatPost).collect(Collectors.toList())));
            }
            return new ProtocolReply(PlainTextFormatter.formatPost(msg));
        }
        return new ProtocolReply("Message not found");
    }
    @UserCommand(pattern = "^(#|\\.)(\\d+)((\\.|\\-|\\/)(\\d+))?\\s([\\s\\S]+)",
    help = "#1234 *tag *tag2 - edit tags\n#1234 text - reply to message")
    public ProtocolReply EditOrReply(User user, String... args) {
        int mid = NumberUtils.toInt(args[1]);
        int rid = NumberUtils.toInt(args[4], 0);
        String txt = args[5];
        List<Tag> messageTags = tagService.fromString(txt, true);
        if (messageTags.size() > 0) {
            if (user.getUid() != messagesService.getMessageAuthor(mid).getUid()) {
                return new ProtocolReply("It is not your message");
            }
            tagService.updateTags(mid, messageTags);
            return new ProtocolReply("Tags are updated");
        } else {
            int newrid = messagesService.createReply(mid, rid, user.getUid(), txt, null);
            return new ProtocolReply("Reply posted.\n#" + mid + "/" + newrid + " "
                    + baseUri + mid + "/" + newrid);
        }
    }

    @UserCommand(pattern = "^(s|u)\\s+#(\\d+)$", help = "S #1234 - subscribe to comments",
            patternFlags = Pattern.CASE_INSENSITIVE)
    public ProtocolReply commandSubscribeMessage(User user, String... args) {
        boolean subscribe = args[0].equalsIgnoreCase("s");
        int mid = NumberUtils.toInt(args[1], 0);
        if (subscribe) {
            if (subscriptionService.subscribeMessage(mid, user.getUid())) {
                return new ProtocolReply("Subscribed");
            }
        } else {
            if (subscriptionService.unSubscribeMessage(mid, user.getUid())) {
                return new ProtocolReply("Unsubscribed from #" + mid);
            }
            return new ProtocolReply("You was not subscribed to #" + mid);
        }
        return new ProtocolReply("Error");
    }
    @UserCommand(pattern = "^(s|u)\\s+\\@(\\S+)$", help = "S @user - subscribe to user's posts",
            patternFlags = Pattern.CASE_INSENSITIVE)
    public ProtocolReply commandSubscribeUser(User user, String... args) {
        boolean subscribe = args[0].equalsIgnoreCase("s");
        User toUser = userService.getUserByName(args[1]);
        if (toUser.getUid() > 0) {
            if (subscribe) {
                if (subscriptionService.subscribeUser(user, toUser)) {
                    listener.userSubscribed(user, toUser);
                    return new ProtocolReply("Subscribed");
                    // TODO: already subscribed case
                }
            } else {
                if (subscriptionService.unSubscribeUser(user, toUser)) {
                    return new ProtocolReply("Unsubscribed from @" + toUser.getName());
                }
                return new ProtocolReply("You was not subscribed to @" + toUser.getName());
            }
        }
        return new ProtocolReply("Error");
    }
    @UserCommand(pattern = "^(s|u)\\s+\\*(\\S+)$", help = "S *tag - subscribe to tag" +
            "\nU *tag - unsubscribe from tag", patternFlags = Pattern.CASE_INSENSITIVE)
    public ProtocolReply commandSubscribeTag(User user, String... args) {
        boolean subscribe = args[0].equalsIgnoreCase("s");
        Tag tag = tagService.getTag(args[1], true);
        if (subscribe) {
            if (subscriptionService.subscribeTag(user, tag)) {
                return new ProtocolReply("Subscribed");
            }
        } else {
            if (subscriptionService.unSubscribeTag(user, tag)) {
                return new ProtocolReply("Unsubscribed from " + tag.getName());
            }
            return new ProtocolReply("You was not subscribed to " + tag.getName());
        }
        return new ProtocolReply("Error");
    }

    @UserCommand(pattern = "^\\s*help\\s*$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "HELP - returns this help message")
    public ProtocolReply commandHelp(User user, String[] input) {
        List<String> commandsHelp = Arrays.stream(getClass().getDeclaredMethods())
                .filter(m -> m.isAnnotationPresent(UserCommand.class))
                .map(m -> m.getAnnotation(UserCommand.class).help())
                .collect(Collectors.toList());
        return new ProtocolReply(String.join("\n", commandsHelp));
    }

    public String getBaseUri() {
        return baseUri;
    }

    public ProtocolListener getListener() {
        return listener;
    }

    public void setListener(ProtocolListener listener) {
        this.listener = listener;
    }
}